Polarized relay.



W. S. HENRY.

POLARIZED RELAY,

APPLIOA lION FILED MAY 6,1911

Patented June .25, 1912.

WI Tit/E8858:

" T all whom it may concern:

UNITED STATES PATENTQFFICE.

'WILLIAM S. HENRY, OF ROCHESTER, NEW YORK, ASSIGNOR TO GENERAL RAILWAY SIGNAL COMBANY, OF GATES, NEW YORK, A CORPORATION OF NEWJYORK.

.PoLARIzEn RELAY,

Specification of Letters Patent.

Application filed May 6, 1911. Serial No.'625,490.

Be it known that I, \ViihllAM S. HENRY, a citizen of the United States, and resident of the city of R chester, in the county of Monroe and Stat lof New York, have invented a new and; useful Polarized Relay, of which the following is at specification.

This invention relates to a relay having a. permanently polarized armature.

Polarized relays of the type to which this invention relates, are. often used in connection with systems, the proper operation of which determines the sa-t'ety of human beings,for which reason absolute certainty'ot action must be attained. At thesame time the device must not be so susceptible to slight jars and shocks as to be continually moving to the abnormal position, thus" .creatmg great annoyance and loss ot tune.

The primary object of the invention is, therefore, to so arrange the magnetic circuits in a polarized relay that a desired movement is certain to occur.

A further object of the invention is to construct a relay o,f the character described in which an air gap will exist between the armature in normal position and an electromagnetto the pole of which it will be at-' tracted when an ab ormal current'tlows.

A further ob ect of the invention '18 to I so construct a relay ofthe character described, that if the permanent magnet loses 1ts permanent magnetism, current ot any polarity flowing 1n the electromagnet \\-'lll cause the armature of the. relay to assume the abnormal position and open the relay contacts.

The nvention consists in the dea of means, a practical embodimentof which is 5 of my invention.

herein illustrated. V In describing in detail the form selecte to illustrate the invention, reference will be had to the accompanying drawings, in which like characters of reference designate like parts, and in which:

Figure 1, is a side elevation of one form Fig.2, is a plan view of the form shown in Fig. 1.

o nstr'uciio'n.--1, designates a piece of magnet steel bent into the form of a' U, properly llaltdctlctl itlltl permanently magnetized in such a manner that end N becomes the north-pole and end S becomes a soutlhpole; 2, designates a softiron member which 1s fastened to the end 'S ,of

member 1, by means of-bolt 3, the bolt having a nut t thereon which, when screwed up,-binds members 1 and 2 firmly together so that they make gtmd nagnetic contact, the bolt 3 being of such .length that it may be passedgthrough a supporting wall, so wliliole device can be supported on a wall" y;screwing the nut- 511p tightly on the bolt onthe opposite side of the wall from'thatiimou which the relay is, a pin (3 being attached to im'en'iber- 2 and being adapted to fit in a suitable hole in the wall the bolt 3 as a pivot. r 3

The member 2 has 'a"'do\\"nwardlyextending lug 2 whichhas aholetherethrough in which is inserted theS'reducedscrew threaded end 'of a cylindrical piece of soft iron 7, th'ere being" a nut 8 scre\ ved upon the reduced end of the 'eylindrical piece on the opp'osit'e side of thelug 2; from that 4 on which the shoulder formedby reducing the end lies, so that by screwing up the nut,

the cylindrical piece 7 'isfirn'ily, held ;to. the lug 2. The'opposite'endof member 7 is also reduced in diameter and bears the enlarged soft iron pole piece 9, forced into place thereon. Upon the core 7 is placed the coil of wire 10, the two terminals ofwhich are desig nated by 10 and 10 I Upon the end N of member 1, is the pivot beat-mg member 11, fastened thereto by means of the bolt 13 and nuts 14 and 15, the

pivot pin being designated by 16, and having an armature 17 mounted thereon for 0scillation, one'end of the armature extending sufliciently to ,the right of the pivot pin as viewed in Fig. 1, so that it may be oscillated manually, the other. end of the armature bearing a good contactmaterial 18 fastened thcretoby a rivet 19, and when in the position shown in l ig. 1, bearing against contact spring 20, the contact spring 20 being held on a block of insulating material 21, by means of binding post The insulating block is fastened to member 2 by means of the projection 2 and thebinding post 23, the binding post 23 making good electrical contact witlrprojectionfi and the armature PatentedJune25,1912.

-to preventtherelay from turning about versible current so that at times there will' be no currenttihwi'ng .in coil 10, at other times a current will be flowing in what will be called the normal direction, while at other times a current may flow in coil in what may be called the abnormal or reverse direction. hen no.current is flexing in the coil 10, the armature '17 will re in in contact with the'end 2 of member 2, or'in contact with pole piece 9, with no tendency to more-in either direction, that is, it is equally attracted by both the end 2 of memher 2 and by the pole piece '9, so-thatif placed in contact with either one of these members, it willurcmain in the moved position. .This action of thc'armature is due to the fact that t1! en'd N of memberl is a nortlrpole and, consequently, the end 2 of member 2 isa. .south-pole, and at the same time the pole piece 9 is also a south-pole; both of these lattcr'being caused to have the permanent-magnet 1, so that the flux from the north-pole of the permanent magnet is divided and flows to the pole piece 9 and to the end 2 of the member 2, so that under normal coriditions the-end of armature 17 bearing the contact material 18 plays between two poles of like polarity, there-- fore,vit would not have a bias to-one more than to the "other and "if placed in-contact with-one, would remain in contact. If CQFIGIIl is caused to flow through the coil 10., in what I have termed the normal direction, tlle polarity of the end N of pin manent magnet 1 will remainthe same, which, as before, will cause the end 2 of member 2 to be a south-pole but the pole piece .9. due to theparticular direction'of the How of current in the coil 10, will becdtne a north-pole and being connected with member 2, v will assist permanent magnet -'-1" t' cause the end 2 of 'member 2 to becoinea' south-pole, so that-under such conditions-there will boa north-pole at the end N of member 1, a north-pole at pole piece 9, and a south-pole at the end 2 of member 2, due to the combined action of the permanent magnet and current flowing in the coil 10, so that the flux tends to flow from both end N of member 1 and pole piece 9 to the end 2 of member 2, thus tending to hold the armature 17 against the end 2 of member 2 causing the contact material 18, to make good-contact with contact spring 20, and so decreases the liability of the ar- ,65 mature 17 being accidentally moved by a such polarity by reason of the influence of the abnormal or reverse direction as it flows in a direction contrary to what it does when flowing in the normal direction, the end N ofpermanent magnet- 1, will remain anorthpole and the pole-piece 9 will become a south-pole, so that the end 2 of member 2 will be acted upon by two contrary forces one exerted by the permanent magnet 1 tending to make end 2 a south-pole, another, exerted by the magnetic flux caused bythe flow of current in coil 10, tending to make ita north-pole, but as the magnetic flhx caused by coil 10, has the stronger effect so upon member 2 than that caused by the permanent magnet 1, the end 2 of member 2 will become a north-pole and, consequently,

.u'ill tend to repel the armature 17 if in contact therewith, as the armature 17' would by influence of the end N of permanent magnet- 1, have a like'polarity, and at the same time an exceedingly strong pull would be exerted by pole piece 9, as it is of south-polarity, to pull armature 17 toward it, so that under such conditions the armature 17- would'be pulled into contact with pole piece 9, thus breaking the contact between spring '20 and .ccntact material 18. It is to be ob served that the stronger the magnetic fiux, caused by coil 10, the greater the pull upon armature l8-and the greater the repulsion toward armature 1S exerted by the end 2 by inernber 2, and these facts should be carefully borne in mind for therein lies to a large extentthe great value of this form of the invention, for in devices of this character heretofore invented and designed to actuate an armature in the manner which has-heretofore been described in this specification, the'greatditiiculty has been that/when an abnormal current of exceedingly great value flowed through the coil or coils of the dcvice, the armature being at that time in contact with a pole directly acted upon by the flux generated by current flowing in the coils of the devices, a local action was set up which held the ar inature iii the position in which it then was, whereas it-should have repelled it, this being due to the fact that the local flux was so much stronger than the fiux generated by the permanent magnet that it virtually excluded the fluxfrom the permanent magnet and the device acted as though itwere simply an electromagnet with-age a soft iron armature of neutral polaritv,

In this device, however, the pole which will v have the greatest tractive effect when an abnormal current 'tlows through the coil of the device, is the pole with which the arma-- turc is when in normal position, not in contact, so that the greater the amount of abnormal current the greater will be the tendency for the armature to move. It is further to be observed that when an abnormal 13o current flows through the coil of the device, the magnetic flux gene 'ated by. said current flows in the same direction as the magnetic flux of the permanent magnet, thus tending to increase the efl'ectof said permanent magnet in transmitting to the movable armature a like polarity as the end to which it is pivoted, thus by creating a stronger unlike pole in the armature to that of the pole to which it should be attracted under such conditions; to-wit: the pole piece 9, greatly increasing the efliciency pf the device. This method of operation also differs from .the polarized relays of the prior art, as heretofore, the flux caused by the electromagnet has, when abnormal current was flowing in the electromagnet, been opposed to the flux caused by the permanent magnet. It is also to be observed'that a large air gap occurs in the path of greatest flux with abnormal current flowing, and as the armature is lightly pivoted and is the only movable iron member in the device capable of bridging this air gap, it will most certainly do so; whereas, in other devices of this type in the prior art, the movement of the armature due to abnormal current does not cause the closing of an air gap in the path of the great-- est flux, they do not, therefore, have the certainty of action inherent in applicants const-ruction.

All relays heretofore constructed employing a permanent magnet, and which depend for their proper operation upon the presence of magnetic flux in the permanent magnet are subject to the dismlvantagc that a body of steel will, in time, lose its magnetism. especially when constantly subjected to a magnetic flux contrary in direction. to thatof the permanent magnetism of the steel, and when the permanent magnet has lost its magnetism, the relay will not operate as intended when a reverse current tlows. 1n relays upon the operation of which the safety of human lives depend such a possibility should be eliminated, but heretofore no means have been devised to overcome such objection. ln applicant's relay such a contingency has been foreseen and fully provided against for it the permanent magnet loses its magnetism the relay contact will then always open when current through its oil regardless of the direction of flow, sothat the act that a magnet has lost its magnetism is instantly made kn wn,

by the impossibility of closing the contact of the relay when current is flowing in either direction in the coil of the relay. it is ttur thermore to be observed that the opening of the relay contact is the safe condition and not the dangerous condition, that is, the relay fails on the safe side. 7

By so constructing the relay that the armature is normally held in a position from which gravity tends to move it, the force required to move it to abnormal position may be lessened by that amount thus rendering the relay more sensitive than devices heretofore constructed, and by having the armature tension a spring such as 20 in the normal position, it' the permanent mag netism of the permanent magnet is lost, the spring 20 will force the armature away from the upper pole with which it is in contact and it will then fall to the lower pole, thus breaking the relay contact, thus also 'ausing the relay to fall on the safe side. In applicants device it will also be seen that the desired result is accomplished by the use of but one coil, whereas in all devices heretofore constructed of this nature, ithas been necessary to employ two coils of wire, and herein appl' 'ant has made a decided advance over the prior art.

Having now illustrated one form of mechanism embodying the principle of the invention, and "having described the same, what I desire to secure by Letters Patent, and what I claim as new is:

1. In a polarized relay, a permanent magnet approximating the form of the letter U, a soft iron extension bolted to one leg of the permanent magnet. and extending in the plane oi the magnet nearly to the other leg of the magnet, a down ardly extending lug on the soft iron extension in proximity to that end fastened to the permanentmagnet, a hole therethrough, a soft iron rod having a reduced screw threaded end passing through said hole and clamped thereto by means of a nut screwed upon said reduced screw threaded end, and extending nearly to the tar leg of the U magnet and in the plane thercoi, and enlarged pole piece of s ft iron atlixed to a reduced portion ofthe other end of said rod, a coil of wire wound about said rod in such a direction that normal current flowing thcrethrough causes said pole piece to be of the same polarity the adjacent. leg of the U magnet, and abnormal current -auses it to be of the opposite polarity. a pivot support fastened to the free leg of the Uinagnet, an armature supported by said pivot approximately midway of its length, one end extending between the pole piece on thr said rod and the near end of the U magnet extension piece, the other end extending outwardly from the leg of the U magnet, the-said inner end bearing a contact strip, a spring contact adapted to bear against said contact strip when said armature bears against said sot't iron extension piece. an insulating bloch borne by the end of said soft iron extension supporting said contact spring, a binding post passing through said insulating block and through said soft iron extension, and a binding post passing through said insulating block and said contact spring, out of contact with said soft ii'on extension piece.

' nent magnet, an iron core attached to one if said permanent magnet loses its permapermanent n'lagnetism.

2. In a relay, a permanent magnet, an nating adjacent the'other limb of the per electromagnet and a movable armature, a manent magn e'thaving a metallic win flow of currentin said electromagnetin a wound thereon, an iron melnber fastened tc normal direction assisting said pernn nentthe first mentioned limb and terminating magnet to hold said armature in one posijust above the end of the said iron core-adtion, a fiow ofcnrrent in said eleetromagnct jacent the other limb, an iron armature pivin a reverse direction causing in conjuncoted to the said'other limb of the permation, with said permanent magnet said arnent magnet and oseil-latable between the mature to assume another position, either of end of the said iron-eore and the end of the said currents in said eleetromagnet causing saidfiron member, an ansfor nmnuallyplaesaid armature to assume said other position, ing said armaturein 'contakct: with either said iron 'eore or said irmrmember, the magnetic force of said magnet holding said armature lllstllC moved position, resilient contacting means engaged by said armature when resting against the end -ol" said iron member adapted to force said armatureaway from rontaeting position when said 'pcrimment magnet loses its permanent: magnetism.

5. in a polarized relay, a U shaped permanent magnet having two iron members attached to one limb, both terminating adjacent the. other limb of the permanent magnet, a metallic wire wound on one of said iron members, a eontset, an iron armature pivoted on the other magnet eseillatable bet-\"veenthe two iron members and held against; said Contact; by the force of the permanent] magnetism: of said magnet, said contactadaptedto force said arnmture from contacting position nent magnetism, said permanent magnet causing said armature to remain in said other position when moved thereto and contacts controlled by said armature. adapted to move said armature from the tirstmentikmed' position it said permanent magnet loses its 3. In a polarized relay, :1 U shaped permanent magnet, an iron core attached to, one limb of the pern'lanent magnet and terminating adjacent the other limb of the permanent magnet having a metallic wire wound thereon, an iron member fastened to the first mentioned limb and terminating just above the end of the said iron core adjacent the other limb, an iron armature pivoted to the said other limb of the permanent: magnet and oscillatable between the end of the said iron core and the end of the said iron member, means for manually placing raid armature in contact with either said iron core or said iron member, the magnetic force of said magnet holding saidm'mature in the moved-position, and a cont aet engaged by said armature when resting against the end of the said iron member exerting a force to move said armature from in, contact with said member.

- 4. In a polarized relay, a U sln1 ')ed-pern'1a-- manent magnetism, a flow or electricity through said Wll'elll onedn'eetion breaking said arnjiature, a flow of electricity in the to maintain said connection.

WILLIAM S. HENRY.

' Witnesses:

' LILLIAN L. PHILLIPS,

limb of the permanent magnet-and termi- Many G. DALBEY.

when said pet'irianentmagnet:iltiises its per said cenneetion between said contaeb'aiid other dl reetion through said wire assisting h nt of the permanent 

